Percentage of observations where the VFR minimums for ceiling and visibility are met: visibility of 5 mi or more and a ceiling of 3,000 ft or more. Only observations between sunrise and sunset are taken into account.
Marginal VFR conditions (%)
Month
Average
2024
2023
2022
2021
2020
January
84.7
78
83
75
75
89
February
85.4
83
94
74
75
98
March
83.2
80
78
76
90
94
April
85.4
83
85
80
97
May
81.3
78
88
84
77
June
91.0
82
97
86
92
July
89.7
85
94
82
91
August
86.8
82
88
89
95
September
77.9
61
66
78
90
October
73.3
78
65
54
81
November
83.4
74
90
92
88
December
74.7
68
58
75
71
Average
83.7
80.5
79.0
82.1
80.9
89.7
Marginal VFR conditions or better during daylight period
Percentage of observations where the MVFR minimums for ceiling and visibility are met: visibility of 3⅛ mi or more and a ceiling of 1,000 ft or more. Only observations between sunrise and sunset are taken into account.
Maximum temperatures (°C)
Month
Average
2024
2023
2022
2021
2020
January
-24.0
-20
-27
-24
-19
-23
February
-27.4
-24
-31
-28
-20
-28
March
-19.6
-15
-15
-19
-22
-20
April
-10.2
-5
-10
-9
-12
May
-3.8
2
-2
-3
-4
June
7.8
8
11
5
7
July
15.0
13
18
13
18
August
12.8
13
13
11
16
September
6.0
7
7
6
5
October
-2.4
-1
-1
3
-3
November
-11.3
-6
-15
-9
-12
December
-18.8
-15
-14
-17
-16
Average
-8.6
-20.3
-5.4
-5.2
-6.8
-6.0
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.